The United States has failed to block a United Nations treaty on preventing torture, but the country is under no obligation to adopt the new convention at home.

Human rights groups want to send out a strong message

The treaty, which would establish a system of unannounced inspections of prisons and detention centres, was adopted by 35 votes to eight at the UN Economic and Social Council, and will now go to the General Assembly for approval.

But even if it is passed here, countries which do not choose to adopt the treaty will not be subjected to such inspections.

The US hostility to a convention which it would not have to subscribe to is being seen as a sign of its deep, ideological opposition to multilateral treaties which it believes would impinge on its sovereignty.

Veto power

It is the second occasion in less than a month that the country has refused to throw its weight behind issues which have widespread support in the international community.

At the end of June, it used its veto in the UN Security Council to block the renewal of the peacekeeping force in Bosnia because of its concerns over the new International Criminal Court (ICC).

It does not want the ICC to have jurisdiction over US soldiers deployed abroad, fearing troops could face malicious accusations of war crimes.

The crisis over the court took place within a context of increasingly fraught relations between Washington and the European Union.

Tensions became particularly apparent earlier this year over the treatment of prisoners captured by US forces in Afghanistan, who were taken to a jail in Guantanamo Bay, Cuba.

There was outrage in Europe after the prisoners were photographed wearing orange jump suits, shackled and kneeling, with goggles over their eyes and masks over their mouths and noses.

The UN treaty on torture would allow outside inspections of such sites, but only if the US were to sign the convention.